Abstract

Iron selenide, Fe1.01Se, the layered parent compound of the recently discovered superconducting arsenide family, has previously been shown to be non-magnetic and superconducting with a critical temperature of 8K. Here we show that copper can be substituted at the iron site in Fe1.01Se up to a solubility limit of 20-30%, after which a first-order transition to the three-dimensional CuFeSe2 structure type is observed. As little as 1.5% copper is sufficient to suppress the superconductivity, and 4% drives the system through a metal-insulator transition. A local magnetic moment is introduced, which maximizes near 12%doping, where a spin-glass transition near 15K is observed.

abstract = "Iron selenide, Fe1.01Se, the layered parent compound of the recently discovered superconducting arsenide family, has previously been shown to be non-magnetic and superconducting with a critical temperature of 8K. Here we show that copper can be substituted at the iron site in Fe1.01Se up to a solubility limit of 20-30{\%}, after which a first-order transition to the three-dimensional CuFeSe2 structure type is observed. As little as 1.5{\%} copper is sufficient to suppress the superconductivity, and 4{\%} drives the system through a metal-insulator transition. A local magnetic moment is introduced, which maximizes near 12{\%}doping, where a spin-glass transition near 15K is observed.",

N2 - Iron selenide, Fe1.01Se, the layered parent compound of the recently discovered superconducting arsenide family, has previously been shown to be non-magnetic and superconducting with a critical temperature of 8K. Here we show that copper can be substituted at the iron site in Fe1.01Se up to a solubility limit of 20-30%, after which a first-order transition to the three-dimensional CuFeSe2 structure type is observed. As little as 1.5% copper is sufficient to suppress the superconductivity, and 4% drives the system through a metal-insulator transition. A local magnetic moment is introduced, which maximizes near 12%doping, where a spin-glass transition near 15K is observed.

AB - Iron selenide, Fe1.01Se, the layered parent compound of the recently discovered superconducting arsenide family, has previously been shown to be non-magnetic and superconducting with a critical temperature of 8K. Here we show that copper can be substituted at the iron site in Fe1.01Se up to a solubility limit of 20-30%, after which a first-order transition to the three-dimensional CuFeSe2 structure type is observed. As little as 1.5% copper is sufficient to suppress the superconductivity, and 4% drives the system through a metal-insulator transition. A local magnetic moment is introduced, which maximizes near 12%doping, where a spin-glass transition near 15K is observed.